SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edcb5455e6b9db5b9b6270a267ec2a8035f05ab05a6012f27e00df38d774926d' 
  AND token = 'abAvhYmZKKPPdCJVRVtrE9+uju6RLBxWEuPriR4QUhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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