SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b68ae23b35f251981b35b482aff6f17130c58742875665b4267df20810c64aa8' 
  AND token = 'Xoi8AmckWscJMw/yBTsDiFlZdNj7JN4QPJ0JIqtQAGc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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