SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b15822d87fd62f08b647f2e6c6d2fa58932fb4ba4d928d42b46504a9b30ad24e' 
  AND token = 'kbu54tw9v8iibpdHskqzGzBhcqyFk1nC92C8x/MpCFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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