SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3fb61b1aae84d06b7428185e343d0319e64ebf04942c2a63196e8f238009fce' 
  AND token = 'r86OuLYp/9uSqXk7rbE8BvRNwvNMXIPenoYjKVVWhCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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