SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c5fad0f2c5e85ba2137380fa7c4bccb95d3c3c7abdd04b89e547f1052369869' 
  AND token = 'ZryRID2yOj4GgpYIqRirzonmQ2yzm3xjj4iskRq2e3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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