SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5214e2e8485f6b589119c47ef17d96629ad636e622a9e8384fce7e600bc091e2' 
  AND token = 'rTH6ca5YosPmEhfJOr/HAwhFVLSXdmz/lbvnezTLZXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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