SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68e77b809ac0d9ada4c79ca74baae41c14431c4e553e50e96f702ad88204a961' 
  AND token = 'OAKFkSUdvZ7u/BwtfXlpQgXetTDP2rjv6li4NvetnJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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