SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5beeb369579f414d22e158a959c54a1e8356d4975f57e7ca401fa31b0fd26f22' 
  AND token = 'FQnMjsNksZfE14spjmtPIN7/jfqMyMg8PMi3VQNlvjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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