SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93c43fce952781f1963f38ecfeb9a40eb9e731dea4bb78558f674c8fe2e47631' 
  AND token = 'MycOmdOcJRgiAp3mwDVvi5Mv3DOZfddXf4cP+gMSniM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}