SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78b1445e3e435d0328539d9569022514c7b27c54ecb1feec95140fa676b14005' 
  AND token = '9o2YLnR4pfIgr1LtEspSvjTBiuG+ibSAHh1DxDKberk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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