SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9dd13eb33869547b6c4bcb1837634779c98e47bc93bb5307b4c171abb2e9f17' 
  AND token = 'LKHNv5wzMqbB3Tbi3qfea5IZG37CREssgiRikGpYXRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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