SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c8dd4db876a59cd31315d66b24ac9dda9fde624db21c60b21227ee0650a2e94' 
  AND token = 'gDGLzhm4rRBWitGrZQgmoHumzFoM5bUrCChs/qTP2VM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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