SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '875484be195ae63422271bc0ed43ba8769518a16089d16a0f037491155c62b38' 
  AND token = '60Am+pipNwRzQWrvm7sstUZ/hqp6A1mgno2lo9I1jW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}