SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23620047959edd73b31c8874d83e780cc6d2070c66ea12ff1af39bbe1a04b3a1' 
  AND token = 'VV15eyUsWNNGawtZ9LWFjP6gC3IdFtTlw1/vukDGmiI=' 
  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"
    }
  }
}