SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a73e39a542b4184952da6df7f859beb17be3747d926f255b910fb7cad6ed30e8' 
  AND token = 'HWI9S+Sjd1wxvV/Sn2k3R1A7BBgArDD/YmY7/i2HyJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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