SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b258eb438ae15cc3c3a28750829e58cf14fd8536355ac2e2533f0bb19623dab0' 
  AND token = '+94Cxw5+KIrnuhUlOBs+lkv6T/bTyYAMCyDf/ARN8CI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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