SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc677e45cefd17548b5430841a9d4ae4e57114498340dc281bd8e044e56f639b' 
  AND token = 'rAbdLQwLwZC/cOgPAoipq4meZU17gHYvj7SVk0utmrE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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