SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb4740f57a61b77111bfe47fb4ee3e9b4c60e27b2d0881dc9a6256538567350e' 
  AND token = 'YqUBX134kSXR0DxU3HQI+axZm395m/yjJHAGf/vSFiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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