SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2d2d7a3544cbbf617e8aed616d3f6d85aba12ae06deb20835368573abc8ce53' 
  AND token = 'PFZKZec23A1gBGPEAgrz8JnE4a2wMAFcHg39PBbInto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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