SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14471e4d42194a9610a31cf2ef53f362ef84a4405afc957fc0fc3350110381fc' 
  AND token = 'vNxvy4ewr618DAHn3W0oTJ8s+XhjqZeR331w9ddSnvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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