SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '572dbfefee64b068aec99c43d9503e0e3ec4808a0d17d661c97133b5cd296e3b' 
  AND token = 'LMEX4pHUzAbzwMPKIrVKXTwaovntpe91P54OwILvrFE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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