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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'aca2ef14a3b5774aa3c645ad5c5ce7cf340836dbfddf375f1f694ad9dc24542a' 
  AND token = 'TkJhHRDgR4ATC6VDXoT2vMzkRjHQ7Yp2VOJ/T7oZuaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}