SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c6974240c066034a80cee7c58543b08143a7bf19beeb0a4b7e21938930c1df9' 
  AND token = 'yqWBwMf/WJ5N9FYiB3yVZExYlfQwOWqcR+kZO5JG/Lw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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