SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5be9c179c13b021111d89db1ef276720e52bc132f62df8ca5eeac6778f5aad3a' 
  AND token = 'CwnzrnbVYgRiPItJBxv4WQKyIDJx8D+WA/pHkFcH3AE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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