SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '771101133a3a5d731d2a8612f24b946b800954e32ef5eedb314ed83e0ec8dad2' 
  AND token = 'ForhibQAVbjDjGc3M6SbVLyTQL7xWBCHRh3Lb6p0Wo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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