SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0950238b31ba74ab0e2cd18c62d0608083b3eb594fb2e2f2d78066cf8354a5bf' 
  AND token = 'MqZ8isF4I+2VIz8x5qn6JsjTFfIBp9U0EHMroWxbYRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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