SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b1aab7f9987773608c31388c7a969484e402cf6a53e0878f19a32931c7950f5' 
  AND token = 'swCsCbPAn1bdM8TjLeUt3tXM1fOVTGWwYzcGQKnQYmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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