SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d0941d88fbc6ed53edc398b5de68efbcf4076b409c13af98c626131757e290a' 
  AND token = 'K4mFzddd+g2RITVJ7lcTCOGhMOvvjnalAFMDWizW7/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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