SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0829d4b43c208da1f23ca6f721e990e547fa543d5dd46cd5f788f851713d671e' 
  AND token = 'JQDd9eybo/+5BLZUoPYivhKyWDZh5CjQ6oF5G/51n5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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