SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d0d0bfd14d2cd58f7381972c682ea1725002b2d5ffef67f541517c4aa651807' 
  AND token = 'i/CFKglYxteSQR+sSfsUOsw4IlvZ8UgmAwVvTmV11Y0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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