SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5af4857b322ee8f17ce2596784edcec32658f4d6db66661f5cd0dae8c5d346f2' 
  AND token = 'ceXxhf+3RIVWM4ckrGAetNFT511gjNYWNaD3uA4VOBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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