SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8449225ba1bc3e912e1058231f14ff5302a1dc431f919cb60573bed30ffd8b78' 
  AND token = 'O7gwc+qmttvYScwUe0S/sqfxB9G+urybnrDpSJF4VPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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