SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '505af0fe5f2b22ec47d68a80eb76f40847e5611696912cb79febb3f8aa3ce81e' 
  AND token = 'BrQg+qvK0XswJzfuT/XCLV8yXO0ejYgGWp79kXXmIlk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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