SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a8e0a7e7f2c18a682ceee1f40e4acc302ab885a9a6421a779a47ebe469faeea' 
  AND token = 'owPsSOm+AtJVyXhLPaDvfGbmNS2Tvi9gLQpC9uYRZ9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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