SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '314ff87ab7974d66580bcfaf6ac4be0a2e6170a91d24320d99f7ddae72ea5ffc' 
  AND token = 'ZhaDPt2Vy1i4IV6T3gAjvHPheaeAlFJDUXdbByAQafY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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