SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44ded8927916ce81f9355f88cca521b488ccb11aef09128b706ee16a0978c30e' 
  AND token = 'XxTSs4Q9fJ2gWcTEcaCAEw3myZ8vNnFucCBhOKE3TyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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