SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1ead2314276f3800450f403713da92ea1c288fe3e5c1235d87efa391b053c2d' 
  AND token = 'cWwnbhiFhye0s758EiV2X/of8N/xD1zWHEU1j2ZPzP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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