SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20e72f3849364a191e206f7840189075b879b129810ed8e4f1123db5505c576b' 
  AND token = 'afM2oi28icMFfXBtfwkMqPaiLko9QzIZ1rx7s3OVz+s=' 
  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"
    }
  }
}