SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eca54a2a7f5e12381c8a4a87657e31be0530b57b31fd5ce2df1e9a0e9b49b7f2' 
  AND token = 'OT/ZRJzqbFiriPl0+jOnzpH10WSqukwDEufhsAvxgVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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