SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c46af821a8ec1753696124c4433ac270d0d4954cb85efa1f8ca22d5aea5e21a' 
  AND token = 'GV/71mthVBrslvRLHxQZ3+pAoTufstkxMF6pSuGqqOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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