SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94fefe4c93de8459661be52cff0ba4b62401cd6913a87cb7757ce38e1445f0b3' 
  AND token = 'EXDew2aKe2hSR+VnWMUSLOZuryVDGpN2xoXq+gWFPpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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