SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd42026a93c29499e410013476101c6672539c346619cbad732eac10d77d928eb' 
  AND token = 'jIzItglqcTTP+WpXgJK8L/4LkaF4vtEI7broNkoCFK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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