SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bd08b60b6a132fdc9f23ca0444f4cc48953581d79af57c270f8d2f807b04e63' 
  AND token = 'Xy76QZVmIXAsF35GkM5Y7wDhPrCUaiYbwAmg7+0veO4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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