SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae385dd1b25e04b2d2896aad9d84270fc1983e921c84cb9f0b08e1dab8f43766' 
  AND token = 'KeZGhtszdX6v25AjSdV59nOKSsitsXYZCftK2fqUrO4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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