SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee73361cf0921cf58eecd1b4089ceae1fd925fce36b0bfc6b4288da4ce12eceb' 
  AND token = 'CNk31TS4jOgnR4vbRIJrxYYOos7ObSmNbExY2nIOqYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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