SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f3cf7664068d280291d72f06537e9279aa97031e6a615dde41d5ec6cf967484' 
  AND token = '/+Skbx9GTGncrHLKhCV8K2n7owKU0r8mWgHY/U1vJow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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