SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32126e73ff125d75f119b5de98d847710d261196b60e198dfbd043cc6b66ed80' 
  AND token = 'tKJLan5+vm0s+jDvJR4VVR2x5lSBQzF3nZ3EuLy0x8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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