SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfb71a496d7c5475250207443f30e12590cc79779d585f804ba805eb5d18e0c0' 
  AND token = 'n2gzFgbu2Ybpz2MT08fw1UiA77Q3O7jJ9TzKCdktfac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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