SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5d6a954d1bebf8fadd060832905c169f8e71ec56bd68197862c9705eb2f6858' 
  AND token = 'swVAkctgNXTPvJLEDzkaJvivLjzfDRowjwGP638Thac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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