SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb5cc01087f9a93dc6c8748f8eae57ff5620a6a1b88bcb9337adf69397f083d0' 
  AND token = 'X053BiPsz47ZtV/g+Ku+qbvby1wv6nbAjIjhF8UIUgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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