SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9071d662bf9ababe62190a2f7397bd3e927ad562a6a1040d99965b61c36a5f02' 
  AND token = 'QhQCDAjpmFeo6WlCF2TCY/DINRCgPs6indICDfv7jno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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